//链表中倒数第k个节点
//输入一个链表，输出该链表中倒数第k个结点。
struct ListNode* FindKthToTail(struct ListNode* pListHead, int k) {
	struct ListNode* cur = pListHead;
	int count = 0;
	while (cur)
	{
		cur = cur->next;
		count++;
	}
	if (k > count)
		return NULL;
	cur = pListHead;
	count = count - k ;
	while (count--)
		cur = cur->next;
	return cur;
}